Drugs in supraventricular tachycardia

I have a friend who has/suffers from Supra ventricular tachycardia. He’s had a few attacks in his life and is in the process of seeing experts about his heart. The recent scans he has had have actually shown that his heart is fine and healthy apart from some ‘faulty wiring’ (which I don’t quite understand) and an ablation could be done to fix that. It’s worth noting he suffers from quite bad anxiety at times and I personally believe this could be the possible cause but doctors don’t seem to accept or address that.

Anyway to the question, for someone who has/has had SVT attacks (around once a year but could be two in a year then not one for another two years) but no known abnormalities scructurally what are the risks of doing say MDMA or LSD? He would love to try MDMA but obviously heart conditions and MDMA are generally a no go but I’m wondering if MDMA would actually be potentially dangerous?

Another point is he gets a bit anxious while smoking weed solely because of his heart and can feel it beating faster and worries him a bit (he generally feels like there’s something really wrong with his heart but I believe it’s the way he actually views it making the problem worse).

Amphetamines and amphetamine derivatives can trigger tachycardia episodes. In a person suffering from SVT antecedents this effect is more likely. Both amphetamine and methamphetamine are contraindicated in persons with cardiac problems, and clinical trials with MDMA exclude also persons with this antecedents. It is difficult to estimate the risk (SVT are more umconfortable than dangerous, in general) but there are reported cases of severe problems: